How to allow a gui to run simultaneous tasks communicating between them?

I am working on an application creating a scatterplot animation. The animation is based on a for loop. Inside this loop first the program erases then it plots points corresponding to the position of one or more accelerometors in the space. A GUI displays this. I have added buttons to pause or to stop the animation. These button communicate with the animation function by using global variables. But it doesn't work when the animation is to heavy, actually the press on one of the button is not take in account until the animation is finished.

Here is the code of the animation function:

global stop
  global isPaused

      for index_begining= tmin_row:tmax_row-1
          cla(handles.signal_plot)              %remove the previous points
          hold (handles.signal_plot,'on')       %keep axes' paramaters
          %plot connector per connector
          for i=1:nmb_connectors
              for j=index_begining:i_end
                  plot3(handles.signal_plot, sig_matrix(j,3*a-2),sig_matrix(j,3*a-1)...
                      ,sig_matrix(j,3*a),'Marker',sensors_data{a,7},'MarkerEdgeColor',...
                      sensors_data{a,8},'MarkerSize',sensors_data{a,9})
              end
          end
          hold (handles.signal_plot,'off')

         if isPaused==true
              uiwait
         elseif stop==true
              cla(handles.signal_plot)
              break
         else
              wt=str2double(get(handles.time_scale,'String'));  %re-calculate each loop to can be changed during operation
              pause(wt)
         end
      end
      cla(handles.signal_plot)

The first for loop define the beginning and the end of the animation. The second loop deals with the number of "sensor" I want to plot. And the third loop allow to plot several points for one sensor.

The code in the button pause (a toggle button) is:

    global isPaused

    a=get(hObject,'Value');
    if a==1
        isPaused=true;
        set(hObject,'String','Replay')
    else
        uiresume
        isPaused=false;
        set(hObject,'String','Pause')
    end

    clear a

and inside the button stop:

global stop
global isPaused

stop = true;
isPaused=false;

set(hObject,'BackgroundColor','r')
pause(2)
set(hObject,'BackgroundColor',[0.94 0.94 0.94])

As I said this works only if the animation is "light", few sensors, few points to plot per sensor. With an heavier animation, if I add a "disp('Stop')" inside the callback of a button, it appears when the animation is done. Stop or pause a finished animation is not very relevant. So if you have any idea to fix this I will appreciate a lot.

I am not sure it could be a solution but in any case I don't have the Parallel toolbox.

Is there a way to do a thread in Matlab on a computer having a single processor?